Coffee mill



Dec. 5, 1 939. L. s. MAEDE 2,182,131

. COFFEE MILL original Filed Aug. 2S, .195s 4 sheets-Sheet 1 Zhwentor Mamam 4 sheets-sheet 2 COFFEE MILL L. S. MAEDE l Filed Aug. 28, 1933 origina 'Dec. 5, 1939.

' Snventor a hk.

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Cttorneg s L A s. MAEDE Dec. 5', 1939.

COFFEE MILL original Filed Aug. 28, 1953 4 sheets-sheet s Snvclitor ldamHWZaf/,ole

Patented' Dec. 5, 1939 PATENT OFFICE COFFEE MILL Leland S. Maede, Brooklyn, N. Y.

Qriginal application August 28, 1933, Serial No. 687,078. Divided and this application January 12, 1937, Serial No. 120,226

2 Claims.

This invention relates to an arrangement of elements whereby coffee is cracked, ground and treated in a ready, economical and improved manner, the resulting nished coee having a better and more readily extractable iiavor than coffee now available on the open market.

The coiee produced by the means hereinafter described contains chaff in substantially the same proportions as occur in the coffee bean, the maniinished coffee for a given weight of beans.

Moreover, the invention does not stratify in shipment or upon being subjected to long continued vibration in the containers so that the purchaser is assured of a desired homogeneous blend.

'Ihe present invention is directed toward an apparatus by means of Which'thecoiiee is subjected to a single grinding operation and the mixing or blending is carried out in such manner that the particles of the finished coiiee are relatively sharp and clean and do not contain as large quantities of dustnor the rounded worn particles which characterize ordinary coffee. Usually, coffee is subjected to a plurality of grinding operations in the presence of chaff and is subjected to considerable aeration. The apparatus of this invention, however, subjects the coiee to but a single grinding' and very little aeration, thereby retaining volatile fiavoring ingredients or constituents in the coiee. The .apparatus of this invention is so arranged that the beans are ground in the absence of chaff, the iinely cracked coffee being removed from the oarser cracked coffee before the chaff is separated therefrom. Means are provided whereby the cracked coiee and the chaff are ground separately and then mixed in such quantity and under such conditions of agitation that there is practically no additional formation of nes. I YA further object of this invention, therefore, is to disclose and provide a grinding apparatus of novel construction and arrangement of elements. The grinding apparatus is adapted to produce coffee having the characteristics iirs't mentioned hereinabove in a very rapid and economical manner.

A further object is to disclose and provide a coiee grinding apparatus of high capacity, great stability and ease of adjustment and the ability to produce a finely divided coiee having numerous distinctive properties described in detail herein.

Another object of the invention is to disclose and provide a. coiIee grinding and treating appaufacturer thereby obtaining a larger yield of ratus including high speed and low speed cracking rolls and grinding rolls, means for adjusting the same, and means for driving the same in a` novel manner.

Another object is to disclose and provide a coffee grinding and treating apparatus including cracking rolls carried in bearings slidably mounted in guiding frames.

A further object of the invention is to disclose and provide an apparatus for grinding and treat-l ing coffee in which the cracking and grinding rolls are carried, slidably mounted bearing blocks positioned in guiding frames in `combination with A shaker screens, means for shaking the shakers, and suction conduits whereby the chaff and coffee are eiiectively separated.

These and other objects, uses, advantages and adaptations of the invention will become apparent to those skilled in the art from the following detailed description.- 20

In order to facilitate understanding of the invention, reference will be had to the appendedl drawings, in which: i

Fig. 1 diagrammatically illustrates the arrangement of elements in the coffee grinding u'nit and the movement of the coffee beans, chaff, etc., during the operation of the apparatus.'

Fig. 2 is a side elevation of the grinding apparatus.

Fig. 3 is a plan View of the motor drive which forms a part of the grinding apparatus. l

Fig. 4 is an enlarged vertical longitudinal section through a portionof the grinding apparatus illustrated in Fig. 2.

Fig. 5 is a horizontal section through one of thev 35 grinding units. y v

Fig. 6 is a vertical' longitudinal section taken along the plane VI-VI of Fig. 5, showing the guiding frame and bearingblock assembly. Fig. 7 is a vertical transverse .sectionV taken along the plane VII- VII of Fig.l 6.l l v Fig'. 8 is a vertical section taken along the plane VIII-VIII of Fig. 4, showing the method of lsuspending the shaker assembly from the body frame /of the grinding apparatus.

As shown in Fig. 1the roasted coffee beans are fed into a hopper l from which they are continuously discharged through the outlets 2 and 3 by means of suitablefeeders such as the feeding rolls 4 and 5. Thelfeeding means insurethe supply and distribution of coffee to the cracking rolls in a uniform and constant manner: The cracking rolls comprise a high speed circumferentially ribbed roll 6 and a' low speed longitudinally ribbed rollfvl.` I fy t The cracked coffee thenA passes onto a shaker screen 8 which is inclined and the cracked c oiee is contacted with the upper portion of the screen.

The'flnely divided cracked coieepasses through the screen 8 onto a chute 9. The larger particles of coffee, together with the chaff, move along the screen 8, the larger particles eventually falling onto a grille work vtermed a string catcher |07. At the point where the chai and large particles would fall off the end4 of the -shaker screen 8, suction is applied through a boot or conduit I I. The suction removes or separatesthe chaff Afrom -the larger particles. The separation of chaii and coffee is substantially complete at this point because it is being made inthe absence of finely v divided coee. AIt is to be noted that any finely divided coffee produced by the cracking rolls 6 .and 1 would have passed through the 'sreem before reaching the point at which the-s'uction is applied. v

The chaff is conveyed, as indicated by the arrows, through a suction fan I2. and into a chai collector I3 from whence it it discharged into a chaff grinder I4. Chaff grinders are known in the art and generally operate by rapidly throwing and brushing the chaff against a foraminous surface or screen.

The grille or string catcher I retains large impurities such as strings, etc., and directs them :away from the grinding rolls. Coiee free from chaff and from coarse impurities is thus directed linto the grinding-rolls which comprise a slow speed circumferentially ribbed roll I5 land a higher speed 'oppositely driven, longitudinally ribbed roll I6. The finishing or grinding. rolls I5 and I6 comminute the'coifee to the required state of division. The ground coffee then passes hopper, cracking rolls and grinding' rolls is ideninto the hopper of, a mixer or normalizer I1 wherein it is intimately but gently mixed with like elements. or parts have been'marked withv like "numerals, ordinals provided with a prime mark distinguishing elements on one-half of the machine from those on the other.

The grinding apparatus ldiagrammatically illustrated in Fig. 1 is shown inmore detail in the other drawings. -The general arrangement of tical to that shown in Fig. 1. The grinding apparatus is preferably `built in duplicate so as to contain ltwo sets of cracking and grinding rolls, -although coee is passed through the grinding rolls but once.

As shown in Figs. 2 and-3, the grndingappa- '.ratus includes a-body frame 20 on which are mounted the duplicate cracking and .grinding rolls. One of the distinguishing characteristics of this apparatus is'themounting of the rolls so that they are easily adjustable and at the same time held withsuilicient rigidity so as to prevent separation of opposing rolls. Both cracking and grinding rolls may be mounted in bearing blocks adjustably positioned. within guiding frames 2| which in turn are also adjustably positionedl on aisaial y the body frame 20. ADetailed construction of the guiding frames and appurtenances is shown in Figs. 6' and 7.

As there shown, the guiding frame 2| is preferably of rectangular form, including top, bottom and end plates'fastened together in a suitable manner as by means of machine screws.

This

guiding frame 2| is adjustably connected to the .body frame as`by means of bolts V22, said boltsl extending through slots 23 formed inthe horizontal portion of the main frame 20. Movably positioned within the guiding frame 2| are bearing blocks 24 and 25, said bearing blocks containing suitable bearings 26 within which the shafts 21 and 28 are journaled. The shafts 21 and 28 may carry thegrin'ding rolls I5 and l5.

Positioned between the bearing blocks 24 and is a set of shims 29. The edges of the shims 29 are protected plates 30.

The end of the outer bearing block 24- rests against an end plate 3| which has a compression spring 32 bearing thereagainst. The compression spring is positioned betweenthe end plate 3| and 'a presser plate 33. The presser plate is A movably positionedwithin the guiding frame 2|,

the adjustment being obtained by means of screws lfrom dustby means of 'cover 34 mounted in internally threaded apertures in the end of the guiding frame 2|. Preferably,I the compression. spring 32. is sufficiently heavy to prevent any appreciable movement of the bearing blocks 24 and 25 relative to each other, the main,v function ofthe compression spring being to dampen vibration.

The spacing between the rolls I5 and I6 carried by the shafts 21 and 28 Ajournaled in bearing blocks 24'and 25 is regulated by the shims 29.

The distance between the rolls can therefore be regulated with great nicety by the introduction or'the removal of the shims. 'I'hese shims may have an individual thickness of. 0.001 inch. In order to facilitate the removal of shimswhenever it is necessary to adjust the rolls relative to each other, the end plate 3| is provided with a boss.

36 in which the end of a rod 31 is firmly attached.

The rod' 31' extends beyond thev guiding frame 2|, the outer end of said rodbeing externally threaded as indicated at 38. Threadedly mounted on the end of this rod is'a sprocket wheel 39, -a thrust bearing 4 ,0 being positioned between the sprocket wheel and the end wall of the guiding frame -2|. sprockets 39 and 39 mounted on rods in opposing guidingframes by a set of rolls so that both end plates in both'guiding frames may be simultaneously moved.

A chain 4| may connect the In order to facilitate the movement of the A guiding frames 2| along the body frame 20, stop' screws 42 may be threaded through a portioxbf Y,

the frame 20, the ends of. the stop screws abutting the end of the 'guiding frame 2|. f'

As shown in Figs. 2, 3, `4 .and 5, the rolls of every unit are driven from opposite ends. For example, the roll |5 is driven from the bottom end (on the drawings) whereas the roll I6 is driven from the upper end. Suchmethod of driving rolls permits the use of V type belting, the high speed rolls being driven from 011ev vsideof ythe machine whereas the low speed rolls are driven from' the other side.- Furthermore,.the use of V belts or roped drive eliminates vibration and facilitates adjustment. Where. gears and pinion are used, it is often necessary to -cut down the gears every ltimethe rolls are cut down for `a major adjustment.

On the present machine, however, the tension in the belt drive may be readily adjusted by moving the guiding frames 2| along the bo'dy frame 2|] in the manner indicated, thereby taking up any slack which may develop in'the belt drive. In adjusting the cracking rolls the two guiding frames 2l may be pulled together yby means of a turnbuckle 43 which engages with the ends of externally threaded rods 44 and 45 carried by the opposing ends of the guiding frames.

y The motor drive consists of a motor 46 mounted in the lower portion of the body frame 20. The motor pulley is connected to a high speed shaft 41 by means of the belt drive 48. The shaft 41 may also carry a gear 49 in mesh with another gear 50 which drives the lowspeed shaft 5I. The shafts 41 and 5I are journaled in hangers carried by a member 52 which is adjustably connected to the body frame 20. The tension of the maindrive belt 48 may therefore be adjustedI by moving the member 52 upwardly.

The shaft 5| may carry. a pulley 53 which is connected by feed belting 54 to the slower of the two grinding rolls, namely, the roll connected to the shaft on which-pulley 55 is mounted. The

same pulley may carry additional belting 56 passing over a larger Apulley 51 mounted on a shaft which carries the slower o'f the two rolls of the cracking unit. The cracking rolls are thus caused to rotate at a lower peripheral speed than the grinding rolls. Similar belting connects the pulley 53 with pulleys 58 and 59, as for example the belting 60 and 6I. 'Obviously, therefore, the belts 54, 56, 60 and 6I may be tightened by moving the guiding Vframes of the grinding rolls outwardly. If it is desired to only tighten belts 56 and 6I, then the upper guiding frames of the cracking rolls may be brought closer together by means of the turnbuckle 43.

A similar arrangement of belting but on the opposite side of the machine connects the high speed rolls of the grinding and cracking units with the high speed shaft 41. In addition, a belt or belts v62 connects the high speed shaft 41 with the pulley 63 which is mounted on a shaft 64 provided with eccentrics 65 and 66, these eccentrics being adapted to impart an easily oscillatory motion to the shaker screen units as will be described hereinafter.

After the coffee has been fed from the hopper I through the outlet 3 by the feeding roll 5 and has passed through the cracking rolls 6 and 1,

it is discharged onto the shaker screen 8. Theshaker screen 8 is inclined and is held within a shaker assembly or housing 61. This lshaker housing is suspended from the main or body frame 20 by elastic hangers. As shown in Fig. 8, the side member of the shaker housingV 61 may be provided with a bracket 68 whereas the main body frame 28 is provided with a horizontally extending bracket 69. The brackets 69, and 68 are connected by means of a rubber hanger 10 whichmay consist of vstrips of rubber clamped at their ends to brackets 68 and 69 as by means of clamping plates 1I and 12 respectively, Such hangers are employed at both the upper and lower ends of the shaker housing 61 and on either side thereof.

The lower and rear portion of the shaker housing 61 is provided with a shaft 13 extending in a horizontal direction and connected to the..l

side members of the shaker housing by means of trunnions 14. The eccentric 65 maybe connected by a shaker-arm 15 with such shaft 13, the end of the shaker arm being -provided with a split bearing housing 16. It is evident, therefore, thatl when the shaft 64 is rotated, the eccentrics 65 will transmit an oscillatory motion'to the shaker housing 61 which, being flexibly supportcd,vwill quietly but vigorously oscillate.

The shaker housing 61 also contains beneath the screen 8 a chute 9, which chute is inclined at a' greater angle than the shaker screen 8.v The lower end of the shaker chute 9 terminatesat a point in feeding relation to tbe grinding rolls I5 and I6.

During the cracking of the coffee by the cracking rolls 6 and 1, chaff is liberated from the beans and some of the beans are cracked to a finer state of division than others. The cracked coffee discharged from the cracking rolls 6 and 1 will therefore fall upon the upper end of the shaker screen 8 and the more finely divided particles of coffee will pass through the shaker screen onto the chute 9, from whence such finer particles are discharged directly into the grinding rolls l5 and I6. At the lower end of the shaker screen 8, only the chaff, large particles of coffee, and impurities such as strings or other larger pieces, remain. At this point suction is applied as by means of a boot or conduit II'. Preferably the boot or conduit II is adjustable so as to assume various positions between the extremes indicated by the dotted lines in Fig. 4. By so adjusting the position of the boot, it is possible to regulate the effect of the suction upon the material falling oif the lower end of the shaker screen withoutv the necessity of modifying the size or speed of the suction fan I2 connected to said conduit II. Furthermore, by adjusting the position of the boot II with respect to the end of the shaker screen 8, the amount of chaff being removed may be regulated and controlled.A

Positioned between the lower end of the shaker screen 8 and the chute 9 and extending beyond the edge of the housing 18 enclosing the grinding rolls I5 and I6, is the string catcher IIJ. The string catcher is mounted in aframe in an inclined position and may consist of small ,round bars capable of permitting larger particles of coffee to pass therethrough but adapted to catch and retain larger particles such as stringsY and other foreign materials. This string catcher may either be mounted as an extension of the shaker housing 61 or it may be stationary. The strings 'and other foreign materials retained by the string catcher are permittedto drop exterio'rly of the housing 18. The larger particles of coffee thus separated from the foreign materials drop into the grinding rolls I5 and I6.

In adjusting the apparatus described hereinabove, it has been found that cracking rolls 6 inches in dameter and 36 inches long give the best results. These cracking rolls are set up to about within 0.012 inch. The grinding rolls, on the other hand, are at least 8 inches in diameter and are set up to about within 0.008 inch of each other. The use of large diameter rolls for grinding increases the grip and permits the maintenance of a uniform grinding or cutting action.

Furthermore, the coffee is more uniformly spread- It has been found thatvinstead of strong springs are used. The springs used in the guiding frames inwhich the grinding rolls are journaled have a 6,000 pound deflection per inch, in an experimental unit made in accordance with this invention. 'I'he use of such a strong spring is important because it keeps the rolls in place and does not permitthem to vibrate, thereby insuring uniformity in operation.

Attention should also be called to the fact that the shaker screen 8 is relatively short. When 6 inch cracking rolls and 8 inch grinding rolls were used, the shaker screen 8 was only 24 inches long. The lise of a short screen of this sort is important in that it prevents the coffee from becoming aerated and losing flavoring characteristics.

After the coffee passes through the grinding or finishing rolls l and f6, it is discharged through theconduit 80 into the mixing unit I1. As pointed out hereinabove, the mixing unit blends the ground coffee with the separately ground chaff at .a low. speed so that the coffee is .not sub-- jected to attrition or rubbing. Coifee thus mixed is then discharged into hoppers which supply the can filling or packaging machine.

. i In my co-pending United States Letters Patent No. 2,085,376,4 of which this application is a division, the method of operation is described in greater detail' and preferred ranges or particle .sizes of coffee are given. It is understood that the apparatus of thisinvention is not limited to use in the manner described in United States Letters-Patent No. 2,085,376, and is capable of being employed in the production of various types of coffee. All changes, modifications and adaptationsthat come within the scope ofthe appended claims are embraced thereby.-

I claim:

1. In a coffee grinding and treating apparatus,

the combination of a body'frame; a cracking unit mounted on said body frame, said cracking unit including a high speed and a low speed `roll; a pair of rectangular. guiding frames mounted on saidbodyframe, each of said guiding frames in-A cluding bearing blocks slidably mounted in the guiding frame and in which the cracking rolls are journaled; shirns between said bearing blocks;

a spring means for holding said bearing blocks and shims together; a grinding unit mounted on said body frame and below said cracking unit,

said grinding' unit including a high speed and a low speed roll; additional guiding frames mounted driving shaft with ends of high speed cracking and grinding rolls on one side ofsaid apparatus, belt means operably connecting said low speed driving shaft with ends ofvlow speed grinding and cracking rolls on the opposite side of said apparatus; and means for adjustably positioning said guiding frames on said body frame for adjustably tensioning said belt means.

2. In :a coffee grinding and treating apparatus, the combinationof: a body frame, a cracking unit mounted on said body frame, said cracking unit including a high speed and a low speed cracking roll; a grinding unit mounted' on said' body frame and below said cracking unit, said grinding unit including a high speed and a low speed grinding roll; guidingy frames containing bearingv blocks in which vsaid grinding rolls are journaled; low speed and high speed driving shafts journaled in bearings mounted on amember carried by said body frame below said grinding unit; belt means operably connecting said high speed driving shaft with ends of high speed grinding and cracking rolls on one side of said apparatus; belt means operably connecting said low speed driving shaft with ends of lowA speed grinding and cracking lrolls on the opposite side of said apparatus, each guiding frame containing a pair of said bearing blocks, said bearing blocks being slidably mounted in such frame,

shims between said bearing blocks, an end plate for one of said bearing blocks, a presser plate movably carried within said guiding frame, a

presser spring between said end plate and presser plate, and means 'for adjustably positioning the presser plate within said guiding frame, the frame on the end opposite'ithe presser plate acting as a stop for the adjacent bearing block; and means for adjustably positioning said guiding frames in which said grinding rolls are journaled on said body frame for adjustably tensioning said belt means.

LELAND S. 

